Project Summary Among people with chronic medical conditions, those with a serious mental illness (SMI) are more likely to have more severe and/or multiple health conditions yet receive a lower quality of care and are less likely to use preventative and primary care services. Poor access to healthcare and the prevalence of social determinants of poor health exacerbate these disparities. The social and economic consequences of SMI increases the risk of chronic unemployment, poverty, social isolation, stress, and discrimination?experiences that can bring about a range of unhealthy behaviors and the onset of associated chronic illnesses (e.g., diabetes). As healthcare systems face increasing challenges to meet the physical and mental health needs of persons disproportionately and negatively impacted by social determinants of health, the Department of Health and Human Service's call to action is to develop effective and cost-efficient ways of addressing social determinants of health. Emerging evidence suggests that peers (persons with lived experiences of mental and physical health conditions and structural inequities) are in a unique position to help individuals with SMI, who live under disadvantaged social and economic conditions, navigate through and around some of the barriers. Our proposal will test a recently- piloted, pragmatic solution that employs a peer-based, Wellness Enhancement (WE) Harambe initiative designed specifically to focus on overall wellness (the 8 dimensions of wellness) and health across multiple social determinants of health. WE Harambee aims to enhance access to, and engagement in, primary and behavioral health services, and improve overall health and well-being, for a population of ?high-utilizing? Medicaid-recipients with SMI who receive care through Behavioral Health Homes (BHH). The intervention provides group education, support, and wellness coaching. In pilot testing, WE Harambee reduced emergency room visits for psychiatric/substance use reasons, reduced alcohol use, improved overall wellness, increased involvement in care planning, and enhanced satisfaction with care. Participants described increased activation, self-efficacy, hope, and connection. The proposed research aims to 1) Conduct a systematic assessment of the degree of fit between the currently developed WE Harambee intervention and the BHH target population; 2) Standardize WE Harambee through further development and adaptation of the intervention protocol and development of fidelity measures through a deployment-focused approach in which end-user feedback is systematically incorporated to refine the intervention and research protocols; and, 3) Pilot test the feasibility, acceptability, engagement of Target Mechanisms, and preliminary effectiveness associated with the WE Harambee intervention and research protocol. Through a pragmatic, stepped-wedge research design, achievement of these aims will provide the preliminary evidence needed to advance to a full scale clinical trial.